Family #73 in the 1834 Grimm census.
1834 Grimm Census 
Katharina Margaretha was born after the 1798 census and married before the 1834 census. This means she was not captured in a census with her biological parents. Unless we find a descendant who has detailed private records or gain access to the right church records, we will probably never know her last name at birth.
Studying the maternal haplogroup of Anna Dorothea's female descendants could help narrow down her maternal ancestry, in that it can eliminate those people who are not a match with the maternal haplotype of her female descendants. This process of elimination is trickier than it sounds, because you need to not only know the haplotype of a direct female descendant, but also of possible matches.
For example, if you are a direct female descendant of Katharina Margaretha, then your maternal haplotype would be Sample A. Next:
Once you narrow the possibilities, you must use other methods to try to confirm if one of them is correct. You may discover that none of them is correct, and then your search will continue.
In this example, it's important to remember that Katharina Margaretha's maiden name was probably not Fiebig, unless she married a paternal cousin. This did happen, but not frequently.
Thus, in the 1834 census record above, the only descendants who would carry the same maternal haplotype would be those who also descended from daughter Anna Katharina Fiebig and her husband, whoever he was.
Katharina Margaretha, her husband Johann Georg, and daughter Anna Katharina Fiebig do not appear in the 1857 census with the rest of the family.  There is an indication that one of the brothers may have passed away and six of his children are listed at the end of family #77.  Because Johann Georg does not appear anywhere else in the 1834 census, it stands to reason that they may be his children, two of whom were females. None of those children is named Anna Katharina. She had probably already married and was living in another household. His wife Katharina Margaretha may have remarried, or she, too, may have been deceased.
Until it can be confirmed that these children were Katharina Margaretha's biological children, one can't rely on a descendant of one of them to have a matching DNA maternal haplotype to that of descendants through Katharina Margaretha Fiebig and her daughter Anna Katharina.
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Margaretha is 41 degrees from Massasoit Wampanoag, 24 degrees from Priscilla Alden, 24 degrees from William Bradford, 26 degrees from Mary Brewster, 24 degrees from Mary Cushman, 23 degrees from Elizabeth Howland, 23 degrees from George Soule, 25 degrees from Myles Standish, 24 degrees from Edward Winslow and 30 degrees from Dave Ebaugh on our single family tree. Login to find your connection.